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Abstract:

A method and apparatus for segmenting medium access control (MAC) service
data units (SDUs) creates enhanced MAC-es PDUs in the enhanced MAC-e/es
sub-layer by concatenating MAC SDUs received from the logical channels.
An enhanced transport format combination (E-TFC) selection entity
controls the concatenation of MAC SDUs into enhanced MAC-es PDUs. When a
MAC SDU is received that is too large to fit into a selected enhanced
MAC-es PDU payload, a segmentation entity segments the MAC SDU such that
the MAC SDU segment fills the remaining payload available in the selected
enhanced MAC-es PDU. The enhanced MAC-es PDU is then assigned a
transmission sequence number (TSN) and multiplexed with other enhanced
MAC-es PDUs to create a single enhanced MAC-e PDU that is transmitted on
the E-DCH in the next transmission time interval (TTI). A HARQ entity
stores and, if necessary retransmits the enhanced MAC-e PDU when a
transmission error occurs.

Claims:

1. A wireless transmit/receive unit (WTRU) comprising:an enhanced medium
access control e/es (MAC-e/es) comprising:at least one segmentation
entity per logical channel configured to segment at least one MAC service
data unit (SDU), wherein a selected MAC SDU is segmented if the MAC SDU
is too large to fit into a selected payload size for a logical channel;a
multiplexing and transmission sequence number (TSN) setting entity
configured to concatenate the at least one MAC SDU or segment of MAC SDU
into at least one enhanced MAC-es protocol data unit (PDU) and to
multiplex the at least one enhanced MAC-es PDU into one enhanced MAC-e
PDU;an enhanced transport format combination (E-TFC) selection entity
configured to control the multiplexing and TSN setting entity such that
the MAC SDUs or segmented MAC SDUs fill the enhanced MAC-es PDU and to
control the transmissions of the enhanced MAC-e PDU in a next
transmission time interval (TTI); anda hybrid automatic retransmission
request (HARQ) entity configured to store and transmit at least one
enhanced MAC-e payload.

2. The WTRU of claim 1 wherein a MAC SDU is a MAC-d sub-layer PDU.

3. The WTRU of claim 1 wherein a MAC SDU is a MAC-c sub-layer PDU.

4. The WTRU of claim 1 wherein a MAC SDU is a radio link control (RLC)
PDU.

5. The WTRU of claim 1, the at least one segmentation entity further
comprises:at least one buffer configured to store a remaining MAC SDU
segment not included in a selected payload.

6. The WTRU of claim 5, wherein one buffer is associated with all
segmentation entities.

7. The WTRU of claim 5, wherein a MAC SDU segment stored in a segmentation
entity is processed at a higher priority than a MAC SDU received from a
logical channel.

8. The WTRU of claim 1, wherein a selected MAC SDU is segmented only if a
resulting segment is larger than a minimum segment size.

9. A method in a wireless transmit/receive unit (WTRU)
comprising:segmenting a least one MAC service data unit (SDU), wherein
the at least one MAC SDU is segmented if the at least one MAC SDU is too
large to fit into a selected payload size for a logical
channel;concatenating the at least one MAC SDU into at least one enhanced
MAC-es protocol data unit (PDU);creating an enhanced MAC-es PDU such that
a segment of a segmented MAC SDU fills an enhanced MAC-es PDU currently
being created;multiplexing the at least one enhanced MAC-es PDU into one
enhanced MAC-e PDU;transmitting the enhanced MAC-e PDU in a next
transmission time interval (TTI); andretransmitting the enhanced MAC-e
PDU when a transmission error occurs.

10. The method of claim 9, further comprising:storing a remaining MAC SDU
segment not included in a selected payload in at least one buffer.

11. The method of claim 10, further comprising:associating a segmentation
entity with each logical channel, wherein the buffer is configured to
store MAC SDU segments from an associated logical channel.

12. The method of claim 10, further comprising:storing segmented MAC SDUs
from all logical channels in one buffer.

13. The method of claim 10, further comprising:assigning a higher priority
to a MAC SDU segment stored in a buffer than a MAC SDU received from
higher layers.

14. The method of claim 9 wherein segmenting a MAC SDU is only performed
if the resulting segment is larger than a minimum segment size.

Description:

CROSS REFERENCE TO RELATED APPLICATIONS

[0001]This application claims the benefit of U.S. provisional application
No. 60/975,596 filed Sep. 27, 2007, which is incorporated by reference as
if fully set forth.

FIELD OF INVENTION

[0002]This application is related to wireless communications.

BACKGROUND

[0003]The third generation partnership project (3GPP) Release 6,
introduced high-speed uplink packet access (HSUPA) to provide higher data
rates for uplink transmissions. As part of HSUPA, a new transport
channel, the enhanced dedicated channel (E-DCH), was introduced to carry
uplink (UL) data at higher rates. Along with the E-DCH, new MAC
sub-layers were introduced within the overall wireless transmit/receive
unit (WTRU) to control the E-DCH transport channel. The new MAC sub-layer
is the MAC-e/es. More specifically, the MAC-e/es is the MAC entity that
handles the data transmitted on the E-DCH. Upper layers configure how the
MAC-e/es is to be applied to handle E-DCH functionality.

[0004]A block diagram of the UMTS Terrestrial Radio Access Network (UTRAN)
MAC-e layer architecture is shown in FIG. 1, a block diagram of the UMTS
Terrestrial Radio Access Network (UTRAN) MAC-es layer architecture is
shown in FIG. 2, and a block diagram of the WTRU MAC-e/es layer
architecture is shown in FIG. 3.

[0005]For each WTRU that uses the E-DCH, one MAC-e entity per NodeB and
one MAC-es entity in a serving radio network controller (SRNC) are
configured.

[0006]FIG. 1 shows a UTRAN MAC-e 100 and a E-DCH scheduling entity 110.
The MAC-e 100 is located in a NodeB and controls access to the E-DCH.
There is one MAC-e 100 in the NodeB for each WTRU. There is only one
E-DCH scheduling entity 110 in the NodeB. The E-DCH scheduling entity 110
manages E-DCH cell resources between WTRUs.

[0008]The UTRAN MAC-es 200 shown in FIG. 2 comprises a reordering queue
distribution entity 210, a reordering/combining entity 220, and a
disassembly entity 230. The UTRAN MAC-es 200 further comprises a macro
diversity selection entity in FDD mode when there is soft handover with
multiple NodeBs. The MAC-es 200 is located in the SRNC and handles E-DCH
specification functionality that is not covered in the MAC-e in the
NodeB. The MAC-es 200 is connected to both the MAC-e and the MAC-d.

[0010]The HARQ entity 310 handles the MAC functions relating to the HARQ
protocol. Specifically, the HARQ entity 310 is responsible for storing
MAC-e payloads and re-transmitting them. The detailed configuration of
the HARQ protocol is provided by the radio resource control (RRC) over
the MAC-control service access point (SAP).

[0011]The multiplexing and TSN setting entity 320 concatenates multiple
MAC-d protocol data units (PDUs) into MAC-es PDUs. Further, the
multiplexing and TSN setting entity 320 multiplexes one or more MAC-es
PDUs into a single MAC-e PDU, to be transmitted in a next transmission
time interval (TTI), as instructed by the E-TFC selection entity 330. The
multiplexing and TSN setting entity 320 is also responsible for managing
and setting the TSN per logical channel for each MAC-es PDU.

[0012]The E-TFC selection entity 330 is responsible for E-TFC selection
according to scheduling information, relative grants and absolute grants,
received from the UTRAN via L1 signaling and a serving grant value
signaled through RRC. The E-TFC selection entity 330 is also responsible
for arbitration among the different flows mapped on the E-DCH. The
detailed configuration of the E-TFC selection entity 330 is provided by
RRC over the MAC-control SAP. As stated above, the E-TFC selection entity
330 controls the multiplexing function of the multiplexing and TSN
setting entity 320.

[0013]Currently, the MAC-e/es selects a number of MAC service data units
(SDUs) from each logical channel and multiplexes the MAC SDUs into a
single MAC-e PDU for transmission. The existing MAC-e/es protocol relies
on the fact that the RLC is configured to deliver PDUs in one or more
predefined sizes. Unfortunately, the use of predefined PDU sizes creates
overhead at higher data rates.

[0014]Accordingly, there exists a need for improved MAC-e/es architecture
in both the UTRAN and WTRU that allows for flexible PDU sizes at the
radio link control (RLC) layer and PDU segmentation at the MAC layer. The
use of flexible PDU sizes and PDU segmentation would allow for higher
data rates in the UL and may reduce header overhead for UL transmissions.

SUMMARY

[0015]Service data units (SDUs) containing data submitted to the MAC
sub-layer are created by higher layers. When the WTRU is configured to
use the E-DCH, the MAC SDU is passed to the enhanced MAC-e/es sub-layer
in the WTRU, which controls data transmitted on the E-DCH. Enhanced
MAC-es PDUs are created in the enhanced MAC-e/es sub-layer by
concatenating MAC SDUs received from the logical channels. The enhanced
MAC-es PDUs are assigned a transmission sequence number (TSN) and then
multiplexed into a single enhanced MAC-e PDU for transmission on the
E-DCH. An enhanced transport format combination (E-TFC) selection entity
controls the concatenation of MAC SDUs into enhanced MAC-es PDUs. When a
MAC SDU is received that is too large to fit into a selected enhanced
MAC-es PDU payload, a segmentation entity segments the MAC SDU such that
the MAC SDU segment fills the remaining payload available in the selected
enhanced MAC-es PDU. The enhanced MAC-es PDU is then multiplexed with
other enhanced MAC-es PDUs to create a single enhanced MAC-e PDU that is
transmitted on the E-DCH in the next TTI. A HARQ entity stores and, if
necessary retransmits the enhanced MAC-e PDU when a transmission error
occurs.

[0016]When a MAC SDU is segmented, the remaining segment of the MAC SDU
that is not included in the next enhanced MAC-es PDU may be stored in a
segmentation buffer or segmentation entity. The stored remaining segment
is then included in a subsequent enhanced MAC-es PDU. For a subsequent
transmission, if the remaining segment of MAC SDU is too large for the
enhanced MAC-es payload, this remaining segment may be segmented again.
In an embodiment, buffered MAC SDU segments are given priority when
enhanced MAC-es PDUs are being created. Segmentation entities are emptied
before more information is requested from the logical channels for
inclusion in a MAC-es PDU. A segmentation entity may be provided for each
logical channel, or alternatively, a single segmentation entity may be
provided for storing MAC-d PDU segments for all logical channels. In the
latter, only segments from one logical channel may be stored in the
segmentation entity at a time. No other segmentation processes should
take place for another logical channel until the data in the segmentation
entity is transmitted. When segmentation occurs, the enhanced MAC-es PDU
may include a segmentation description in addition to the TSN. The
segmentation description indicates whether a segment is included in the
enhanced MAC-es PDU and whether there are more segments to follow.

[0017]In the UTRAN, enhanced MAC-e PDUs containing MAC SDUs or segments
thereof are de-multiplexed into enhanced MAC-es PDUs at the enhanced
MAC-e sub-layer located in the NodeB. After de-multiplexing, the enhanced
MAC-es PDUs are processed in the enhanced MAC-es sub-layer located at the
RNC. The enhanced MAC-es PDUs are reordered by their associated queues in
a reordering queue distribution entity then reordered by sequence number
per logical channel according to their TSN. A disassembly entity then
disassembles the concatenated MAC SDUs and/or MAC SDU segments. A
reassembly entity reassembles MAC SDU segments into the complete MAC SDU
and then directs all complete MAC SDUs to the proper higher layer entity.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]A more detailed understanding may be had from the following
description, given by way of example in conjunction with the accompanying
drawings wherein:

[0022]FIG. 4 is a block diagram of a WTRU enhanced MAC-e/es in accordance
with a first embodiment;

[0023]FIG. 5 is a block diagram of a WTRU enhanced MAC-e/es in accordance
with a second embodiment;

[0024]FIG. 6 is a block diagram of a UTRAN enhanced MAC-es in accordance
with a first embodiment;

[0025]FIG. 7 is a block diagram of a UTRAN enhanced MAC-es in accordance
with a second embodiment;

[0026]FIG. 8 is a block diagram of a UTRAN enhanced MAC-e in accordance
with a first embodiment;

[0027]FIG. 9 is a block diagram of a UTRAN enhanced MAC-es in accordance
with a first embodiment;

[0028]FIG. 10 is a block diagram of a WTRU enhanced MAC-e/es in accordance
with a third embodiment; and

[0029]FIG. 11 is a block diagram of a method of segmentation of packets at
the MAC layer.

DETAILED DESCRIPTION

[0030]When referred to hereafter, the terminology "wireless
transmit/receive unit (WTRU)" includes but is not limited to a user
equipment (UE), a mobile station, a fixed or mobile subscriber unit, a
pager, a cellular telephone, a personal digital assistant (PDA), a
computer, or any other type of user device capable of operating in a
wireless environment. When referred to hereafter, the terminology "base
station" includes but is not limited to a Node-B, a site controller, an
access point (AP), or any other type of interfacing device capable of
operating in a wireless environment.

[0031]FIG. 4 is a block diagram of a WTRU enhanced MAC-e/es 400 in
accordance with a first embodiment. The WTRU enhanced MAC-e/es 400
comprises a HARQ entity 410, a multiplexing and TSN setting entity 420,
an E-TFC selection entity 430, and at least one segmentation entity 440,
440n.

[0032]The HARQ entity 410 is configured to store enhanced MAC-e PDUs and
retransmit them. The detailed configuration of the HARQ protocol is
provided by the radio resource control (RRC) over the MAC-control service
access point (SAP).

[0033]The multiplexing and TSN setting entity 420 is configured to
concatenate multiple MAC SDUs or segments thereof into enhanced MAC-es
PDUs. In one embodiment, the multiplexing and TSN setting entity 420 may
segment a MAC SDU to fill an enhanced MAC-es PDU as instructed by the
E-TFC selection entity 430 if a MAC SDU is too large to fit into a
selected payload size for a specific logical channel.

[0034]Further, the multiplexing and TSN setting entity 420 is configured
to multiplex one or more enhanced MAC-es PDUs into a single enhanced
MAC-e PDU, to be transmitted in a next TTI, as instructed by the E-TFC
selection entity 430. The multiplexing and TSN setting entity 420 is
further configured to manage and set the TSN per logical channel for each
enhanced MAC-es PDU.

[0035]The E-TFC selection entity 430 is configured to control E-TFC
selection according to scheduling information, relative grants and
absolute grants, received from the UTRAN via L1 signaling and a serving
grant value signaled through RRC. The E-TFC selection entity 430 is
further configured for arbitrating different flows mapped on the E-DCH.
The detailed configuration of the E-TFC selection entity 430 is provided
by the RRC over the MAC-control SAP. As stated above, the E-TFC selection
entity 430 controls the multiplexing function of the multiplexing and TSN
setting entity 420.

[0036]As stated above, the WTRU enhanced MAC-e/es comprises at least one
segmentation entity 440, 440n. More specifically, there is one
segmentation entity 440, 440n for each logical channel in each WTRU.
The segmentation entity 440, 440n is configured to segment MAC SDUs.
As shown in FIG. 4, in one embodiment, the segmentation of the MAC SDU
may occur prior to multiplexing and TSN setting an UL transmission.

[0037]The segmentation entity 440, 440n may segment a MAC SDU if the
SDU is too large to fit into a selected enhanced MAC-e payload as
instructed by the E-TFC selection entity 430. For a subsequent
transmission, if the remaining segment of MAC SDU is too large to fit
into a selected enhanced MAC-e payload as instructed by the E-TFC
selection entity 430, this remaining segment may be segmented again.
Further, the segmentation entity 440, 440n may segment a MAC SDU
based on a remaining payload for each logical channel.

[0038]Each segmentation entity 440, 440n may comprise a buffer
configured to store a segment of a MAC SDU after the segmentation of the
MAC SDU. After the segmentation of the MAC SDU, a segment of the MAC-SDU
is transmitted and the remaining segment is stored in the buffer. In a
preferred embodiment, each buffer contains data belonging to at most one
MAC SDU at any given time.

[0039]Alternatively, there may be only one buffer for all segmentation
entities 440, 440n containing data from only one logical channel. As
a result, a MAC SDU may not be segmented for any another logical channel
until the data in the buffer is transmitted.

[0040]Preferably, the multiplexing and TSN setting entity 420 is
configured to prioritize a stored segment of a MAC SDU when creating the
enhanced MAC-es PDU for the logical channel. The multiplexing and TSN
setting entity 420 includes the stored segment of the MAC SDU in an
enhanced MAC-es PDU before requesting more data from the logical channel
to which this MAC SDU belongs. Once all the stored MAC SDU segments are
included in a enhanced MAC-es PDU, more data may be requested from the
logical channel. According to this embodiment, a maximum of two MAC SDU
segments per logical channel may be included in one enhanced MAC-e PDU.

[0041]FIG. 5 is a block diagram of a WTRU enhanced MAC-e/es 500 in
accordance with a second embodiment. The WTRU enhanced MAC-e/es 500
comprises a HARQ entity 510, a segmentation, multiplexing, and TSN
setting entity 520, and an E-TFC selection entity 530. In contrast to the
first embodiment, the segmenting entity is incorporated with the
multiplexing and TSN setting entity forming the segmentation,
multiplexing, and TSN setting entity 520. The segmentation, multiplexing,
and TSN setting entity 520 may have one buffer for each logical channel.
Alternatively, the segmentation, multiplexing, and TSN setting entity 520
may have one buffer for all logical channels.

[0042]With the introduction of the segmentation entity, described above,
the enhanced MAC-es PDU created may include a segmentation description or
segmentation status field in addition to a TSN field. The segmentation
description field may indicate whether a segment is included in the
created enhanced MAC-es PDU. In addition, the segmentation description
field may indicate whether additional segments are expected.

[0043]There may be restrictions placed on the segmentation functions in
the WTRU enhanced MAC-e/es. For example, any one of the following
restrictions may be used individually or in combination with another
restriction to restrict segmentation functions in the WTRU enhanced
MAC-e/es.

[0044]The support of segmentation functions in the WTRU enhanced MAC-e/es
may be configured for a logical channel, for a MAC-d flow, or for the
entire WTRU enhanced MAC-e/es. For example, when two logical channels,
the dedicated control channel (DCCH) and the dedicated traffic channel
(DTCH), are carried over E-DCH, segmentation functions may only be
allowed for the DTCH and segmentation functions may not be allowed for
the DCCH, or vice versa. The WTRU enhanced MAC-e/es may be configured to
support segmentation functions using L3 signaling or the WTRU enhanced
MAC-e/es may be preconfigured to support segmentation functions.

[0045]In addition, logical channels that are used in states other than the
CELL_DCH state may be configured not to support segmentation functions.
For example, the common control channel (CCCH) may be configured not to
support segmentation functions. Further, for a logical channel, the
enhanced MAC-es may be configured such that no reordering functions or
reassembly functions are performed. As a result, the enhanced MAC-es may
only disassemble a PDU if concatenation has been performed.

[0046]As an optional embodiment, the WTRU enhanced MAC-e/es may be
configured not to insert a TSN number in the header of a enhanced
MAC-e/es PDU or not increment a TSN number in the header of a enhanced
MAC-e/es PDU. Also, the UTRAN enhanced MAC-e and UTRAN MAC/es may be
configured not to support segmentation functions.

[0047]Furthermore, the support of segmentation functions in the WTRU
enhanced MAC-e/es may only be supported for scheduled or, alternatively,
non-scheduled flows. For example, if a first service is mapped to a
non-scheduled grant at the same time a second service is mapped to a
scheduled grant, segmentation functions may only be allowed for the
non-scheduled first service instead of the scheduled second service.

[0048]Moreover, different segmentation thresholds may be defined to
restrict segmentation functions in the WTRU enhanced MAC-e/es. A minimum
SDU size may be defined as a MAC SDU size for which segmentation is
allowed such that any MAC SDU smaller than minimum SDU size is not be
segmented. A minimum segment size may be defined as the minimum size for
MAC SDU segments such that the WTRU enhanced MAC-e/es is restricted from
segmenting a MAC SDU if a remaining segment is smaller than the minimum
segment size. A maximum segment size threshold may be defined as the
maximum size for MAC SDU segments.

[0049]Additionally, other restrictions may be placed on the segmentation
functions. For example, there may be limitations on the number of logical
channels that may be segmented. Further, the number of MAC SDU segments
placed in a logical channel may be limited.

[0050]FIG. 6 is a block diagram of a UTRAN enhanced MAC-es 600 in
accordance with a first embodiment. The UTRAN enhanced MAC-es 600
comprises a reordering queue distribution entity 610, a
reordering/combining entity 620, a disassembly entity 630, and a
reassembly entity 640. The MAC-es or enhanced MAC-es 600 is located in
the SRNC or controlling radio network controller (CRNC) and handles E-DCH
specification functionality that is not covered in the MAC-e or enhanced
MAC-e in the NodeB. More specifically, the MAC-es and enhanced MAC-es
perform the reassembly of segmented MAC SDUS. For each WTRU, there is one
enhanced MAC-es in the SRNC.

[0051]The reordering queue distribution entity 610 is configured to route
enhanced MAC-es PDUs to a correct reordering buffer based on the SRNC or
controlling radio network controller (CRNC) configuration.

[0052]The reordering/combining entity 620 is configured to reorder
received enhanced MAC-es PDUs according to a received TSN and NodeB tags.
The NodeB tags may include a connection frame number (CFN) or subframe
number. After receiving the enhanced MAC-es PDU, enhanced MAC-es PDUs
with consecutive TSNs are delivered to the disassembly entity 630. Each
logical channel has a reordering/combining entity 620. Enhanced MAC-es
PDUs that are received out of order may be reordered in any number of
ways obvious to those of skill in the art.

[0053]The disassembly entity 630 is configured to disassemble enhanced
MAC-es PDUS. The disassembly of a enhanced MAC-es PDU includes the
removal of a enhanced MAC-es header. A disassembled enhanced MAC-es PDU
may contain multiple MAC SDUS, or segments thereof.

[0054]The reassembly entity 640 is configured to reassemble segmented MAC
SDUs and deliver these SDUs to a correct higher layer entity. The
reassembly entity 640 is coupled to the reordering/combining entity 620.
The reassembly entity 640 is configured to reassemble segmented MAC SDUs
and deliver these reassembled SDUs to the correct higher layer entity
after macro-diversity reordering/combining is performed. As a result, the
packets received by the reassembly entity 640 are in order and, if
segmented, may be recombined.

[0055]The UTRAN enhanced MAC-es 600 further comprises a macro diversity
selection entity in FDD mode when there is soft handover with multiple
NodeBs. As a result, the reordering/combining entity 620 receives
enhanced MAC-es PDUs from each NodeB in an E-DCH active set.

[0056]As shown in FIG. 6, in a preferred embodiment, the disassembly
entity 630 is located before the reassembly entity 640. The disassembly
entity 630 is further configured to disassemble a enhanced MAC-es PDU and
forward the disassembled MAC-SDUS, or segments thereof to the reassembly
entity 640. Then, the reassembly entity 640 is configured to reassemble
segmented SDUs and forward all complete SDUs to the higher layers.

[0057]FIG. 7 is a block diagram of a UTRAN enhanced MAC-es 700 in
accordance with a second embodiment. The UTRAN enhanced MAC-es 700
comprises a reordering queue distribution entity 710, a
reordering/combining entity 720, and a reassembly entity 730. In contrast
to the first embodiment, only the reassembly entity 730 is introduced
into the enhanced MAC-es 700. However, the reassembly entity 730 includes
the functions of the disassembly entity described hereinbefore in FIG. 6.

[0058]FIG. 8 shows a block diagram of an enhanced MAC-e 800 and an E-DCH
scheduling entity 810. As stated above, the enhanced MAC-e 800 is located
in a NodeB and controls access to the E-DCH. There is only one E-DCH
scheduling entity 810 in the NodeB. The E-DCH scheduling entity 810 is
configured to manage E-DCH cell resources between WTRUs. Based on
scheduling requests, scheduling grants are determined and transmitted
from the E-DCH scheduling entity 810. The enhanced MAC-e is connected to
the enhanced MAC-es. The enhanced MAC-e 800 and the E-DCH scheduling
entity 810 handle HSUPA specific functions in the NodeB.

[0059]The UTRAN enhanced MAC-e 800 shown in FIG. 8 comprises an E-DCH
control entity 820 and a HARQ entity 840. The E-DCH control entity 820 is
configured to receive scheduling requests and transmit scheduling grants
based on the scheduling requests. The HARQ entity 840 handles the MAC
functions relating to the HARQ protocol. The HARQ entity 840 is
configured to support multiple HARQ processes. Each HARQ process is
responsible for generating ACKs and NACKs indicating the delivery status
of E-DCH transmissions.

[0060]In contrast to the existing UTRAN MAC-e, a de-multiplexing function
is removed from the UTRAN enhanced MAC-e 800. The de-multiplexing
function is instead present in the enhanced MAC-es. As a result, both the
de-multiplexing function and a reassembly function are performed in the
enhanced MAC-es.

[0061]FIG. 9 is a block diagram of a UTRAN enhanced MAC-es 900. The UTRAN
enhanced MAC-es 900 shown in FIG. 9 comprises a reordering queue
distribution entity 910, a reordering/combining entity 920, a disassembly
entity 930, a reassembly entity 940, and a de-multiplexing entity 950.
The enhanced MAC-es 900 is located in the SRNC and handles E-DCH
specification functionality that is not covered in the enhanced MAC-e in
the NodeB. The enhanced MAC-es 900 is connected to both the enhanced
MAC-e and the MAC-d.

[0062]The reordering queue distribution entity 910 is configured to route
enhanced MAC-es PDUs to a correct reordering buffer based on the SRNC
configuration.

[0063]The reordering/combining entity 920 is configured to reorder
received enhanced MAC-es PDUs according to a received TSN and NodeB tags.
The NodeB tags may include a CFN or sub-frame number. After receiving the
enhanced MAC-es PDU, enhanced MAC-es PDUs with consecutive TSNs are
delivered to the disassembly entity 930. Each logical channel has a
reordering/combining entity 920. Enhanced MAC-es PDUs that are received
out of order may be reordered in any number of ways obvious to those of
skill in the art.

[0064]The disassembly entity 930 is configured to disassemble enhanced
MAC-es PDUs. The disassembly of an enhanced MAC-es PDU includes the
removal of a enhanced MAC-es header. A disassembled enhanced MAC-es PDU
may contain multiple MAC SDUs or segments thereof.

[0065]The reassembly entity 940, as described above, is configured to
reassemble segmented MAC SDUs and deliver the MAC SDUs to a correct
higher layer entity. The reassembly entity 940 is coupled to the
reordering/combining entity 920. The reassembly entity 940 is configured
to reassemble segmented MAC SDUs and deliver these reassembled SDUs to
the correct higher layer entity after macro-diversity
reordering/combining is performed. As a result, the packets received by
the reassembly entity 940 are in order and, if segmented, may be
recombined.

[0066]In an alternative embodiment, the reassembly entity 940 is further
configured to disassemble enhanced MAC-es PDUs. As a result, a separate
disassembly entity 930 may not be required.

[0068]The UTRAN enhanced MAC-es 900 further comprises a macro diversity
selection entity in FDD mode when there is soft handover with multiple
NodeBs. As a result, the reordering/combining entity 920 receives
enhanced MAC-es PDUs from each NodeB in an E-DCH active set.

[0069]FIG. 10 is a block diagram of a WTRU enhanced MAC-e/es 1000 in
accordance with a third embodiment. The WTRU enhanced MAC-e/es 1000
comprises a HARQ entity 1010, a multiplexing and TSN setting entity 1020,
an E-TFC selection entity 1030, and a segmentation and sequence number
(SN) setting entity 1040. In contrast to the first and second embodiments
described above, a single segmentation entity, the segmentation and SN
setting entity 1040, is used for all logical channels. As shown in FIG.
10, the segmentation and SN setting entity 1040 is located after the
multiplexing and TSN setting entity 1020.

[0070]The segmentation and SN setting entity 1040 is configured to segment
a multiplexed MAC SDU, if the SDU is too large to fit into a selected
enhanced MAC-e payload as instructed by the E-TFC selection entity. For a
subsequent transmission, if the remaining segment of MAC SDU is too large
to fit into a selected enhanced MAC-e payload as instructed by the E-TFC
selection entity 1030, this remaining segment may be segmented again.
Further, the segmentation and SN setting entity 1040 may segment a
multiplexed MAC SDU based on a remaining payload for the logical
channels. The segmentation and SN setting entity 1040 segments
multiplexed MAC SDUs for all logical channels.

[0071]The segmentation and SN setting entity 1040 may comprise a buffer
configured to store a segment of a MAC SDU after the segmentation of the
multiplexed MAC SDU. After the segmentation of the multiplexed MAC SDU, a
segment of the multiplexed MAC SDU is transmitted and the remaining
segment is stored in the buffer for transmission in a subsequent TTI.

[0072]The segmentation and SN setting entity 1040 may further be
configured to include a SN in a segmented and multiplexed MAC SDU. The
inclusion of the SN may permit the UTRAN to reorder segments prior to
de-multiplexing. However, the inclusion of a SN in a segmented and
multiplexed MAC SDU is optional. Further, the UTRAN may reorder segments
based on information provided by the HARQ entity 1010.

[0073]FIG. 11 shows a method of segmentation in an enhanced MAC-e/es
sub-layer in a WTRU. When a MAC SDU is received from a higher layer that
is too large for the selected payload for an enhanced MAC-es PDU
currently being created, the MAC SDU is segmented as shown in block 1101.
MAC SDUs or segments of MAC SDUs are concatenated to create an enhanced
MAC-es as indicated in block 1103. While creating an enhanced MAC-es PDU,
MAC SDUs received from the higher layers may be segmented to fill an
enhanced MAC-es currently being created as in block 1105. When the
remaining payload of an enhanced MAC-es PDU currently being created is
smaller than a MAC SDU received from the higher layers, the received MAC
SDU may be segmented such that a segment of the received MAC SDU fills
the remaining payload available in the enhanced MAC-es PDU currently
being created. Multiple enhanced MAC-es PDUs are then multiplexed into a
single enhanced MAC-e PDU as shown in block 1107. The enhanced MAC-e PDU
may include MAC SDUs or segments thereof. The enhanced MAC-e PDU is then
transmitted at the next TTI as in block 1109. If an error is detected in
the transmission of the enhanced MAC-e PDU, a HARQ process retransmits
the enhanced MAC-e PDU until successful transmission occurs as in block
1111.

[0074]In a further embodiment, a MAC-d sub-layer comprises a segmentation
entity. The segmentation entity in the MAC-d is configured to segment RLC
PDUs based on E-TFC selection performed at the MAC sub-layer. The MAC-d
header for segmented RLC PDUs may include a segmentation related
information. For example, the MAC-d header may include a segmentation
indicator. Further, the MAC-d header may include information regarding
the number of segments comprising the segmented RLC PDUs or whether more
segments are expected.

[0075]In a further embodiment, an enhanced MAC-es sub-layer is configured
to multiplex multiple logical channels into a MAC-d flow. As a result, an
enhanced MAC-es PDU may contain MAC SDUs from different logical channels
belonging to the same MAC-d flow.

[0076]Additionally, the enhanced MAC-es sub-layer is further configured to
perform segmentation and TSN numbering for a MAC-d flow instead of a
logical channel. As a result, the MAC-d flows may be multiplexed together
in the enhanced MAC-e sub-layer.

[0077]Accordingly, the UTRAN enhanced MAC-e is responsible for
de-multiplexing an enhanced MAC-e PDU into enhanced MAC-es PDUs and
directing the enhanced MAC-es PDUs to the appropriate MAC-d flow.
Further, the responsibility of the UTRAN enhanced MAC-es modified. For
example, the reordering of enhanced MAC-es PDUs is now performed for a
MAC-d flow. Next, the enhanced MAC-es PDUs are reassembled and/or
disassembled as described above. Then, a de-multiplexing entity in the
enhanced MAC-es configured for de-multiplexing the enhanced MAC-es PDUs
into the MAC SDUs and routing the MAC SDUs to a correct logical channel.

[0078]Although features and elements are described above in particular
combinations, each feature or element can be used alone without the other
features and elements or in various combinations with or without other
features and elements. The methods or flow charts provided herein may be
implemented in a computer program, software, or firmware incorporated in
a computer-readable storage medium for execution by a general purpose
computer or a processor. Examples of computer-readable storage mediums
include a read only memory (ROM), a random access memory (RAM), a
register, cache memory, semiconductor memory devices, magnetic media such
as internal hard disks and removable disks, magneto-optical media, and
optical media such as CD-ROM disks, and digital versatile disks (DVDs).

[0079]Suitable processors include, by way of example, a general purpose
processor, a special purpose processor, a conventional processor, a
digital signal processor (DSP), a plurality of microprocessors, one or
more microprocessors in association with a DSP core, a controller, a
microcontroller, Application Specific Integrated Circuits (ASICs), Field
Programmable Gate Arrays (FPGAs) circuits, any other type of integrated
circuit (IC), and/or a state machine.

[0080]A processor in association with software may be used to implement a
radio frequency transceiver for use in a wireless transmit receive unit
(WTRU), user equipment (UE), terminal, base station, radio network
controller (RNC), or any host computer. The WTRU may be used in
conjunction with modules, implemented in hardware and/or software, such
as a camera, a video camera module, a videophone, a speakerphone, a
vibration device, a speaker, a microphone, a television transceiver, a
hands free headset, a keyboard, a Bluetooth® module, a frequency
modulated (FM) radio unit, a liquid crystal display (LCD) display unit,
an organic light-emitting diode (OLED) display unit, a digital music
player, a media player, a video game player module, an Internet browser,
and/or any wireless local area network (WLAN) or Ultra Wide Band (UWB)
module.

Patent applications by Christopher R. Cave, Verdun CA

Patent applications by Diana Pani, Montreal CA

Patent applications by Paul Marinier, Brossard CA

Patent applications by Stephen E. Terry, Northport, NY US

Patent applications by INTERDIGITAL PATENT HOLDINGS, INC.

Patent applications in class Using messages having an address field as header

Patent applications in all subclasses Using messages having an address field as header